The present disclosure herein relates to nonvolatile memory devices, and more particularly, to nonvolatile memory devices.
A nonvolatile memory device retains stored data even when power supply is cut off and includes a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically EPROM (EEPROM), and a Flash Memory Device, among others. Among them, the flash memory device electrically programs and erases data using Fowler-Nordheim tunneling or channel hot electron injection. A flash memory device may have memory cells of various types and may be classified into a NAND type and a NOR type based on a cell array structure. In addition, the flash memory device may be divided into floating gate type flash memory devices and charge trap type flash memory devices according to kinds of a memory storage layer constituting a unit cell.